var container = document.getElementById('itemList');
var ul = document.getElementById('ul');
var timer = null;
// 轮播函数
function roll() {
    if(!timer) {
        var count = 0;
        timer = setInterval(function(){
            count -= 1;
            ul.style.top = count + 'px';
            if (count <= 0) {
                count = 50;
                var flag;
                flag = ul.children[0].cloneNode(true);
                ul.removeChild(ul.children[0]);
                ul.appendChild(flag);
            }
        }, 100)
    }
}
roll();

var oBox = document.getElementsByTagName('body')[0];
 
touch.on(oBox, 'tap', function(e) {
     this.style.background = "red";
     alert('屏幕被点击了');
});